Gas turbines are a type of axial-flow rotary machines. As described in Patent Literature 1, for example, the gas turbine includes a rotating shaft rotating around an axis, an inner casing having an annular shape around the axis, and an outer casing having an annular shape around the axis and forming a gas flow passage between the outer casing and the outer peripheral side of the inner casing. An intake duct is provided on a suction side which is the end in the axial direction of the gas turbine. The intake duct has a flow passage formed therein which has an annular shape around the axis, and an intake opening formed on the radially outside relative to the axis.
The intake duct is connected with the outer casing and the inner casing of the gas turbine, and is supported by this gas turbine in an overhanging state.